An electrical unit may be, in particular, an assembly for measuring currents and for forwarding preprocessed measurement signals to a superordinate evaluation electronics or control system. Assemblies of this kind are connected, in particular, to shunt resistors for the purpose of measuring currents. The current to be measured then flows through the shunt resistor and a voltage is measured across the shunt resistor, which voltage in turn permits a conclusion to be drawn about the current.
To date, press-in pins have been welded onto a shunt resistor of this kind. In a molding process, this component would then be connected together with plug terminals to form a thermoplastic housing. In order to ensure the leaktightness of shunt press-in zones which are formed in the process, the surface was partially laser-treated and then partially cast and cured. The populated printed circuit board was pressed into a housing of this kind and a cover was welded on by means of a laser.
However, the procedure known to date has several disadvantages. Firstly, the electrical unit is located in a cavity. Moisture diffusing into said cavity can lead to migration, to corrosion and to short circuits. The ultrasonic welding technique typically cannot be used as a connection technique for bridges, pole terminals and cable outputs owing to the settling of the printed circuit board. The large number of different processes are costly and resource-intensive.